This invention concerns a device for use on a floating vessel and, particularly, a device capable of restraining lateral movement of equipment being raised or lowered through the well of the vessel. More specifically, the invention concerns a device for use on a floating drilling vessel to restrain lateral movement of a subsea BOP stack being raised or lowered through the well of the vessel.
The possibility of injury to personnel and damage to large subsea equipment, such as BOP stacks and risers and/or main structure members, in the celler deck of floating vessels, such as semisubmersible drilling vessels, is extremely high when retrieving or running such subsea equipment during rough weather. A solution, which minimizes personnel danger and possible equipment and structural damage and yet permits operations to continue, is to stop the subsea equipment from swinging in the well of the floating vessel by means of a capturing device. Because of the large forces involved it is necessary that such device be capable of first cushioning and slowing horizontal movements of the subsea equipment and, second, of holding the subsea equipment stationary. For optimum and efficient use such device must be quick acting and be so constructed and located that it will not interfer with normal functions, e.g. drilling operations, of the vessel. The device of the present invention satisfies all of the foregoing requirements.